Freckles are small, tan to brown macule that can turn dark when exposed to sunlight.
Histopathologically, these lesions demonstrate increased epidermal melanin without increasing in melanocytes.
Freckles are benign lesions that have no propensity of transformation to malignancy unlike lentigo.
Cause and Risk Factors
Freckles appear due to increase in number of melanosomes. These melanosomes are subcellular structures in melanocytes where melanin pigments are produced. While freckles present with hyperpigmentation, the number of melanocytes are not increased in freckles as opposed to lentigo.
Freckles are common in individual with red,blond hair and fair complexion.
Symptoms and Clinical Presentations
On clinical examination, freckles appear as small, well-demarcated hyperpigmented macules that are usually 2 to 4 mm in diameter.
As mentioned, they occur most frequently occur in individuals with red or blond hair with fair skin. Typically appear during early childhood on sun-exposed skin mostly involving areas like the face, hands (dorsum), and upper trunk.
One characteristic feature that differentiate freckles from other pigment lesion of skin like lentigo is that freckles usually increase in number, size, and extend of pigmentation during the summer months and are smaller, lighter, and fewer in number in the winter when there is less sunlight.
Diagnosis:
Freckles are usually diagnosed clinically.
Histologically, there is a normal number of melanocytes with large size and number melanosomes, resembling those seen in dark-skinned individuals.
Treatment and Managements
The main stay of management of freckles include sun-protective measures. Additional treatments are typically for cosmetic purposes only.
Topical retinoids and depigmenting agents may help lighten lesions to a minimal extent.
Pigment-specific lasers and light-based therapy are additional therapeutic modalities that can be used to treat freckles.